How can blacksmith attach copper letters to steel sign without galvanic issues?

A. If the sign will be indoors like in a shop or a mall it may not be a real problem, Shannon. But for outdoor exposure I think it will be. I would suggest that the back of the letters could be tapped and holes be drilled in the steel plate, and plastic screws come in from the back to hold the letters in place.

This may offend a blacksmith who is used to sledgehammers and anvils, though :-)

You also need the tiniest of gaps between the letters and the sign so they are not in electrical contact. One layer of electricians tape would do it.

Good luck and please send us a picture of it. We'll be happy to post it even if you decide my idea was hare-brained and you came up with a better one. In that case we'd probably post it tiny instead of big though :-)

Thanks! I forgot to send you the finished project pic --

He did end up raising the letters to make them stand out a bit more and using a super adhesive between the layers....

Wow, he does nice work!

Regards,